cache.php

<?php

class CacheModel extends Phalcon\Mvc\Model
{

	static protected $_cacheKey;

	static protected $_cacheLifetime = 3600;

	public static function getCacheKey($parameters)
	{

		if (isset($parameters['di'])) {
			unset ($parameters['di']);
		}

		return get_called_class() . md5(serialize($parameters));
	}

	public static function findFirst($parameters = null)
	{
		if ($parameters) {
			$di = \Phalcon\DI::getDefault();
			$cache = $di->getCache();
			$key = self::getCacheKey($parameters);
			$record = $cache->get($key);
			if ($record===null) {
				$record = parent::findFirst($parameters);
				$cache->save($key, $record, self::$_cacheLifetime);
			} else {
				$di->getModelsManager()->initialize($record);
			}
		} else {
			$record = parent::findFirst($parameters);
		}
		return $record;
	}

	public static function find($parameters = null)
	{
		if ($parameters) {
			$di = \Phalcon\DI::getDefault();
			$cache = $di->getCache();
			$key = self::getCacheKey($parameters);
			$record = $cache->get($key);
			if ($record===null) {
				$record = parent::find($parameters);
				$cache->save($key, $record, self::$_cacheLifetime);
			} else {
				$di->getModelsManager()->initialize($record);
			}
		} else {
			$record = parent::find($parameters);
		}

		return $record;
	}

}

class Robots extends CacheModel
{

	public function initialize()
	{
		$this->hasMany('id', 'RobotsParts', 'robots_id');
	}

}

class Parts extends CacheModel
{

	public function initialize()
	{
		$this->hasMany('id', 'RobotsParts', 'robots_id');
	}

}

class RobotsParts extends CacheModel
{
	public function initialize()
	{
		$this->belongsTo('robots_id', 'Robots', 'id');
		$this->belongsTo('parts_id', 'Parts', 'id');
	}
}

$di = new \Phalcon\DI\FactoryDefault();

$ev = new Phalcon\Events\Manager();

$connection = new \Phalcon\Db\Adapter\Pdo\Mysql(array(
	'hostname' => 'localhost',
	'username' => 'root',
	'password' => '',
	'dbname' => 'phalcon_test'
));

$ev->attach('db', function($event, $connection){
	if ($event->getType() == 'beforeQuery') {
		echo $connection->getSqlStatement(), PHP_EOL;
	}
});

$connection->setEventsManager($ev);

$di['db'] = $connection;

$di['cache'] = function() {

	//Cache data for one day by default
	$frontCache = new \Phalcon\Cache\Frontend\Data(array(
		"lifetime" => 86400
	));

	//Memcached connection settings
	$cache = new \Phalcon\Cache\Backend\File($frontCache, array(
		"cacheDir" => "./unit-tests/cache/",
	));

	return $cache;
};

$robot = Robots::findFirst(1);
if (!is_object($robot)) {
	die ('no robot');
}

$robotsParts = $robot->getRobotsParts();
if (!is_object($robotsParts)) {
	die ('no robot');
}

$robot = Robots::findFirst(1);
if (!is_object($robot)) {
	die ('no robot');
}

$robot = Robots::findFirst(2);
if (!is_object($robot)) {
	die ('no robot');
}

$robot = Robots::findFirst(3);
if (!is_object($robot)) {
	die ('no robot');
}